1-digit + 1-digit (eg. 6 + 8)
Sums across 10
Make 10 strategy (eg. 67 + 4)

Strategies for adding two-digit numbers mentally:

1. Make a Ten:
Borrow from one number to make a ten in the other:
Example: 37 + 8 = 37 + 3 + 5 = 40 + 5 = 45.
2. Compensation:
Add or subtract a small amount to one number to make the problem easier:
Example: 36 + 15 = 36 + 14 + 1 = 50 + 1 = 51.
3. Break Apart Numbers:
Add the tens and ones separately:
Example: 38 + 25 = (30 + 20) + (8 + 5) = 50 + 13 = 63.

Practice is key: The more you practice, the faster and more efficient you’ll become at mental math. Choose the strategy that works best for you: Different problems might lend themselves to different approaches.

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### More Mental Math Addition Worksheets

Mental Math Worksheet #1
Mental Math Worksheet #2

Missing Addend (eg. __ + 7 = 15)
Missing Addend, Multiples of 10 (eg. 22 + __ = 30)

Add 3 numbers (make 10) (eg. 5 + 3 + 5)
Add 3 single digit numbers (eg. 4 + 7 + 8)

More Printable Worksheets

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